This sign is posted at a boat launch on Lake Lanier where boating accidents claimed the lives of three children last summer in Buford, Ga. / David Goldman, AP

by Larry Copeland, USA TODAY

by Larry Copeland, USA TODAY

It's not just the highways: With the summer recreational boating season just getting underway, several states are moving to cut down on boating under the influence.

Alcohol use is the leading contributing factor in fatal boating accidents, according to the U.S. Coast Guard. It was the main factor in 17% of the 651 deaths involving registered recreational vehicles in 2012; that was a slight uptick from 16% the year before.

National Safe Boating Week begins Saturday, and some states are moving to reverse the deadly trend:

Georgia on Wednesday lowered its blood-alcohol content limit for boaters from 0.10% to 0.08%, the same threshold for drivers; it also enacted harsher penalties for those convicted of boating while intoxicated. "We believe getting a drunk boater off the water gets a drunk driver off the roads," said Harris Blackwood, director of the state's Governor's Office of Highway Safety."That's because they're eventually going to head back to shore and most likely get in their car."

The Illinois Legislature just passed a bill that authorizes the state to suspend a person's driver's license if the person is caught operating a motorboat while intoxicated; it extends the concept of "implied consent" to test suspected intoxicated boaters involved in injury or fatal accidents. Both houses gave unanimous approval to the measure and it's now before Gov. Pat Quinn, a Democrat. "This is meant to deter the reckless behavior that is resulting in deaths and injuries every year on Illinois lakes and rivers," Democratic state Sen. Julie Morrison said.

Washington Gov. Jay Inslee, a Democrat, on Thursday signed into law a bill that aligns the state's boating under the influence law with its DUI law. The bill adds penalties for boaters found to be under the influence of marijuana and extends the implied consent concept to boaters.

Efforts such as these often follow horrific drunken boating crashes that galvanize public opinion.

Georgia became the 47th state with the same blood-alcohol content threshold for boaters as for drivers after a drunken boating crash on Lake Lanier last June that killed two boys. Griffin Prince, 13, and his brother, Jake, 9, were with family and friends on a pontoon boat when it was rammed by a fishing boat operated by Paul Bennett, who was indicted in August on charges including homicide by vessel and boating under the influence; his trial is pending. Jake was killed in the crash; Griffin's body was found in the lake after nine days of searches.

Morrison said she introduced the Illinois bill after her 10-year-old nephew, Antonio "Tony" Borcia, was killed last summer on Petite Lake. He was being towed on an inner tube by his father driving a pontoon when he fell into the lake. Three of his siblings and his father watched in horror as a 29-foot powerboat operated by David Hatyina slammed into the boy. Hatyina pleaded guilty to operating a boat under the influence of alcohol and cocaine; he is to be sentenced next month.

"You talk about collateral damage, this all-American family is devastated," Morrison said. "The kids and their dad had gone to the lake and Mom stayed at home. She got a call from the boat telling her that her child is dead. This family is going through that."

With her bill, Morrison said, "we are going to try to change the culture."

The culture is already changing to some degree, said Washington Sen. Mike Padden, a Republican who introduced his state's new bill. "There is more and more of an awareness," he said. "I don't think we're in the same place as with drunk driving, but it gets closer and closer."

The recreational boating culture is changing, too, according to one longtime marine police officer.

"You have a lot of what I call the soccer moms out on the water with their children and their families," said John Fetterman, director of law enforcement for the Lexington, Ky.-based National Association of State Boating Law Administrators. Those families "aren't willing to take that risk" of potentially having their safety compromised by intoxicated boaters, he said.

"Years ago, if you were intoxicated and you were boating, we'd probably tell you to go home," said Fetterman, who was a Maine Marine Patrol officer for 32 years. "Today, if you're boating and you're over 0.08 (blood-alcohol content), you're going to jail."